1. Field of the Invention
The present invention relates to a liquid painting instrument for applying a liquid such as a hair dye.
2. Prior Art
Conventional hair coloring instruments such as those as shown in FIGS. 8 and 9, include an outer shaft 1, an inner shaft 1 which contains a hair dye therein and is axially movable in the outer shaft, a brush 3 fixed on the front end of the outer shaft 2, and a valve 4 interposed between the inner shaft 1 and the brush 3. The valve 4 is arranged to be opened so that the hair dye may be supplied from the inner shaft 1 to the brush 3 when the inner shaft 1 is advanced with respect to the outer shaft 2 by pushing forward a knocking member 5 arranged rearward of the inner shaft 1.
In such liquid painting instruments, to prevent the liquid from undesirably discharging from the inner shaft 1 with the knocking member 5 knocked forward (for example, when the instrument is dropped), measures such as that shown in the above drawings, include a projection 7 provided on the inner face of the opening of a tail plug 6 inlayed in the rear end of the outer shaft 2, and both a vertical groove 8 of axial direction and a lateral groove 9 of circumferential direction provided on the outer periphery of the knocking member 5 to receive the projection 7. The projection 7 may be located in the vertical groove 8 to allow knocking motion when the instrument is used. When not used, the projection 7 may be located in the lateral groove 9 to disable the knocking with the knocking member 5 rotated.
However, such known instruments still experience the undesired liquid discharge because the inner shaft 1 containing the liquid, as a result of its own weight, tends to be independently displaced by inertia (i.e., when dropped) without being pushed by the knocking member 5. Further, even if the inner shaft 1 can be prevented from such forward advancement by other means, there still exists the possibility of discharge due to dimensional dispersion in that the inner shaft can move forward a little. Therefore, completely preventing the undesirable discharge of the liquid is difficult.
In addition, formation of the vertical and lateral grooves 8, 9 on the outer periphery of the knocking member 5 involves impairs the good appearance of the instrument and thus is not desirable from a design viewpoint.
Accordingly, the present invention is aimed at providing a liquid painting instrument, without impairing its good appearance, that is capable of preventing the liquid from being undesirably discharged even if the inner shaft 1 is advanced by inertia due to its own weight. The present invention is also capable of completely preventing the liquid from being discharged even when there still exists some possibility for the inner shaft 1 to be advanced a little due to dimensional dispersion.